Presented at the 2017 International Geoscience and Remote Sensing SymposiumWe use multiple satellite observations and numerical simulation to investigate the upper ocean response to Typhoon Kalmaegi in 2014 in the South China Sea (SCS). In this study, significant sea surface temperature (SST) decreasing is observed, which is caused by typhoon-induced vertical mixing and upwelling. The maximum SST cooling is 2°C on the right of the typhoon track since inertial currents rotate in the same direction as the surface wind vectors. We also find an interesting phenomenon that salinity decreases ranging between 0.3 and 0.6 psu on the left side of the typhoon track. We use numerical simulations and in-situ observations to further confirm that salinity reduction is caused by heavy rainfall.